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Jul 24 2012

Fun with thermodynamics

For us science wonks thermodynamics is the study of heat and work and those properties of substance related to heat and work. But for creationists, it’s the basis for a prized whopper endlessly passed off as fact in the fundamentalist jihad against natural history. A recent editorial offers up the classic zombie lie:

York Daily Record — Truth that has been scientifically demonstrated beyond doubt is called a “scientific law” such as the second law of thermodynamics, which states that “over time order tends to disorder.” By the way, this “scientific law” directly disputes the “theory” of progressive evolution.

So much fail in only two sentences. The Second Law of Thermodynamics (SLoT) could be loosely described as a postulate based on the statistics of vast sets of vibrating and moving molecules interacting with one another. Or, one way to state it mathematically is that dS = dQ/T, where dS is the change in entropy, dQ the incremental heat transfer, and T the total temperature of a system. Since most people don’t have a clue what that means, it works great for creationists looking to fool people. I’ve seen a common bait and switch con and a rarer, more sophisticated one. Let’s do the complicated one first, because it’s more fun.

One way to get your lay arms around the SLoT comes from everyday life: heat does not, on average, flow from cold objects to hot objects. This is common sense. A glass of soda does not usually get warmer while the ice cubes in it get colder, right? 

But air contained in a box can get colder while the air outside the box gets warmer, with the right mechanical arrangement and given an input of work. The contraption shown in schematic above is just such a device, one known intimately to any sophomore undergraduate engineering or physics major as a heat pump; it’s also highly valued down here in Texas in July! Think of it as the energy reverse of a familiar steam engine: in the engine heat input produces work output, in the pump work input produces heat output. 

I’ve seen creationists sketch these basics out and then proclaim that we clever humans can break the SLoT afterall, with the sheer power of our awesome monkey brain, and so ‘intelligent design’ is vindicated. The reality is heat pumps use the thermal properties of a coolant undergoing compression and expansion in such a way that heat is still always flowing from a hot substance to a colder one. Air conditioners designed by man, and organisms crafted by natural selection, do not  “break” the second “law” anymore than helicopters or butterflies break the law of gravity.

The less sophisticated con job is oddly a little more difficult to explain. The SLoT can be stated, clumsily, as ‘the entropy in a closed and bounded system will always increase’. But recall from above that entropy is a slippery mathematical quantity, dS=dQ/T, measured as Joules per degree Kelvin in the metric system, and that’s a little too technical for popular discussion. So scientists and science writers have tried using other, more familiar words and concepts when explaining it to the public. And one of the words they’ve tried using over the years is disorder.

Disorder is a lousy term for an elegant quantity. Calling entropy disorder when trying to explain the SLoT to non-science people is about as accurate as using the hand-sign for ‘lovely’ when trying to explain a symphony to a deaf six year-old. It’s terribly prone to confusion with the colloquial idea of disorder, i.e., unorganized, a random mess, or simple as opposed to complex. Unless of course you are a creationist, in which case creating confusion is arguably the whole point of your profession.

Creationist bank on that dual meaning, that entropy is disorder and disorder is the opposite of organization. A bacterium is obviously more complicated than salt water, complex cells more organized than simple bacteria, vertebrates more complex than an amoeba, etc. It’s then easy to erroneously mix in a little abiogenesis with your pseudo evo-bio, and viola, the creationist can now say chemicals to microbes to man evolution violates the SLoT! In the hands of dedicated professional liar that spiel can sound quite intimidating. It even has the added benefit of playing on Hoyle’s tornado in a junkyard fallacy.

There are so many things wrong with that it’s hard to know where to start, each one would take time and some technical detail to get across. Suffice it to say if thermo worked like that — where every physical interaction of matter and energy must go from more to less “organized” at every scale at all times — forget about evo, everything from hurricanes to planetary accretion to developing blastocyst would be impossible.

I doubt the writer quoted above had an inkling of the physics behind heat pumps or entropy. Odds are, like most people, he might appreciate the science if it were explained. But unlike most people, who tend to know when they don’t know, he is probably dead certain that thermodynamics disprove evolution, and that no one who studies physics or biology thought of that, or was willing to admit it, until his creationist mentors were kind enough to enlighten the entire scientific world.

22 comments

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  1. 1
    richardelguru

    Flanders and Swan have by far the best explanation of SLoT.
    It’slot of fun!

  2. 2
    richardelguru

    Sorry about the vid.
    That was the result of a quick search.
    It’s best if you turn away from your screen and just pretend you’re listening to it on the wireless or your gramophone.

  3. 3
    gordona

    Er, the link seems to be to a letter to the editor criticising an editorial. Not quite as reprehensible of the paper methinks!

  4. 4
    Your Dogma is Showing

    Unless of course you are a creationist, in which case creating confusion is arguably the whole point of your profession.

    my first lol of the day. thanks.

  5. 5
    docsarvis

    Excellent explanation of the SLoT. One of the best I have read for a lay audience. Of course, the entire point about Evolution and the SLoT is moot because the Earth isn’t a closed system. No need to get technical, just go outside and look up on a clear day. If that doesn’t work then this essay might, depending on the fundie’s willingness to engage brain.

  6. 6
    machintelligence

    I am rather fond of the gambler’s version of the three laws of thermodynamics:
    1. You can’t win.
    2. You can’t break even.
    3. You can’t get out of the game.
    They don’t translate perfectly, but they are fun.

  7. 7
    den1s

    So now I am left wondering what creationists believe is actually taking place in a heatpump if it’s breaking the SLoT. Magic?

  8. 8
    slc1

    Of course, the real fallacy in the creationist entropy argument against evolution is that they conveniently neglect to mention that it only applies to a closed system. Of course, the earth is not a closed system as there is an external source of energy, namely the sun.

    Consider the following experiment. Place 2 pans of liquid in the refrigerator over night, one containing alcohol and the other water. They will obtain the same temperature by the following morning. Then take the two pans out in place them in the sun. Because the specific heat of alcohol is lower then water, the pan of alcohol will reach the ambient temperature before the pan of water does. Before both liquids reach the ambient temperature, there will be a temperature difference between them which in theory could be used to run a heat engine, i.e. do work. Since the initial condition was incapable of doing work, the interim condition is at a lower entropy then the initial condition. According to the arguments of the creationists, the experiment I just described is impossible!

  9. 9
    Gregory in Seattle

    I like your example. Now when I hear creationists blathering about the Second Law of Thermodynamics, I can ask them if their air conditioning is a lie of Satan.

  10. 10
    left0ver1under

    An old favourite says it best:

  11. 11
    Randomfactor

    On this subject, I’ll ask a question I’ve always wondered about.

    What IS entropy?

    Does it fit into a particular noun/category? Like if I asked “What is a cat?” the answer could be: a cat is a particular type of mammal animal. Or “What is happiness?” the answer might be slipperier, but happiness is a positive emotional state.

    So what IS entropy? Not a law, I assume; a statistical trend? A mathematical concept? A fnord?

    (Same again, “What is chaos?”)

  12. 12
    Skip White

    The science-fail in this letter to the editor isn’t the least bit surprising, as Dover, PA is also in York County.

  13. 13
    Trebuchet

    Good post, Stephen, but that refrigeration diagram is awful! Not to mention almost completely wrong.

    It shows “cooled refrigerant” flowing from the compressor. Which actually produces HOT, compressed refrigerant, which is then cooled by a heat exchanger (not shown) and allowed to expand, cooling it further.

    By the way, your first name is still spelled wrong in the biography box over on the right.

  14. 14
    peterh

    @ #6:

    I’ve been told it’s

    You cannot win,
    you cannot change the rules,
    you cannot leave the game.

  15. 15
    robb

    @randomfactor:
    in statistical mechanics you can show that the entropy related to the number of states accessible to a system.

    S=k ln W

    where k is Boltzman’s constant and W is the number of states.

    what you do to determine the entropy is look at all the particels in the system and determine how many ways the momentums, positions etc can be divided. count them all. that is W. if there are a lot of states for the system to be in, entropy is high. if not, it is low. this is the origin of the “amount of disorder” definition for entropy.

    as for the SLoT, it is not a “law” like other laws. since it is statistical in nature, it *is* possible for entropy to suddenly decrease. for instance, heat can flow from cold to hot.

    for very small systems of few particles, this can happen. for large systems where you have on the order of Avogadro’s number of particles, it is *extremely* unlikely for entropy to decrease spontaneously-as in near zero chance in billions of multiples of the age of the universe.

  16. 16
    drdave

    #6 machine…

    This is the I was taught the three laws:

    1. You can never win, you can only break even.

    2. You can only break even at absolute zero.

    3. You can never reach absolute zero, therefore you neither win nor break even.

  17. 17
    mck9

    There’s nothing wrong with describing entropy as a measure of randomness or disorder. The notion can be expressed more rigorously, as robb has pointed out, and that approach turns out to be equivalent to the more conventional treatment taught in chemistry class. However “randomness” is good enough for a hand-waving discussion for a non-technical audience.

    The important point is this: no law prohibits a local decrease in entropy, as long as you pay for it with an increase of entropy somewhere else. That’s how complex, low-entropy systems like living things can arise and grow from high-entropy raw materials. That’s how water can freeze in your fridge; the equipment extracts entropy from the freezer and pumps it into the rest of the kitchen (and into the back yard if you have air conditioning).

    The extracted disorder is not very noticeable because it’s so, well, disordered. Typically it takes the form of a small and diffuse rise in temperature, or thermal radiation into outer space. The low-entropy
    bits it leaves behind get more attention, but their increased complexity doesn’t come for free.

    If the naive creationist view of thermodynamics were correct, then grass could never grow, and water could never freeze.

  18. 18
    gordonmacginitie

    My favorite euphemism for the Second Law is:
    “There is no such thing as perpetual motion”
    which disproves creationism.

  19. 19
    bad Jim

    You have to understand the authoritarian mindset. It’s a LAW, so it’s obviously an eternal inviolable truth, unlike a mere theory.

    They don’t understand that scientific laws are generally ad hoc characterizations requiring a theory for explanation, as Boyle’s laws are explained by atomic theory, or Kepler’s laws of planetary motion are explained by Newton’s theory of motion and his law of gravitation.

    Another thing that attracts them to the second law is that they get the connection between entropy and information exactly backwards. They start from the premise that humans were perfect at the creation and everything has deteriorated since Adam’s original sin. Therefore it’s intuitively obvious that information has been lost since that point because entropy has been increasing.

    They don’t get that Wheeler linked entropy to information because simple, orderly states can be compactly described and complex, disorderly states can not. A completely random string cannot be represented by a shorter string. The point that noise and complexity are in a certain sense formally indistinguishable doesn’t mesh with their preconceptions, so they insist that entropy means that information continually decreases.

  20. 20
    bad Jim

    Oops, sorry. Claude Shannon, not Wheeler.

  21. 21
    alanuk

    This is a huge and complex topic – some day I would like to write a book about it.

    Creation Science depends on the creationist having a sufficiently inadequate understanding of science to get things wrong in the first place (that is the most charitable way of expressing it) and the punter in the pew having even less understanding.

    In the case of thermodynamics, there is a further twist. The Creation Scientist does not understand it, the punter in the pew is absolutely clueless (but not unimpressed) while the scientifically literate are operating on the limit of their understanding. Even those who use it in their daily work may only have a deep understanding of the subject just applied to their own work; what the creationists are saying may seem wrong but falling outside of their sphere of knowledge. Added to this, the subject has been very badly taught in the past.

    In general, once the 19th century/Creationist/Bad Teaching idea of ‘disorder’ has taken root, all is lost. Mixing the term ‘entropy’ as used specifically in the 2nd Law with the term ‘entropy’ as used in Information Theory, further muddies the water. The problems that arise are illustrated by the forgoing thread. Thermodynamics as a study depends on very clear definitions – substitute hand-waving and confusion ensues.

    Creationists have kept this one going for over 40 years. Originally it was a simple: 2nd Law (Law of Entropy) says disorder (entropy) increases, therefore evolution is impossible. As the error in this was pointed out the story was changed to accommodate it. But as their opponents had made further errors, rather than pointing them out (could they even see them?) creationists (Henry Morris in particular) wove them into their story.

    Henry’s legacy is a cunning tale of words which takes the obvious criticisms into account by the careful weaving of words. In particular, by addressing irrelevant and erroneous criticism, he has distracted attention away from the real problems.

    Thus the current ‘theory’ accepts that everything (except evolution) actually happens and has ‘explanations’ of why trees grow etc. ‘in accordance with the 2nd Law’ and why the ‘fact that the Earth is an open system’ is not a problem. What all this talk covers up is that the original intention was to show that the 2nd Law ‘proves’ that evolution is ‘impossible’ and all this talk has failed to address it.

  22. 22
    bryansanctuary

    I met a guru who claimed he could make order out of randomness by the power of thought alone. His experiment was to take a pot of boiling water and make it freeze.

    He claimed partial success because he was able to lower the boiling pot to room temperature.

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